Stomach pain—pain felt between the chest and groin, also called abdominal or belly pain—is extremely common and often not serious. According to MedlinePlus, milder causes include gas, indigestion, constipation, food intolerance or food poisoning, stomach flu (viral gastroenteritis), and irritable bowel syndrome.
Localized or more severe pain can signal problems in organs such as the appendix, gallbladder, stomach (including ulcers or GERD), kidneys, pancreas, or intestines, and some gynecologic conditions. How intense the pain feels does not always match how serious the cause is, so sudden severe pain, a rigid abdomen, bloody stools, persistent vomiting, or pain with fever needs prompt medical care.